The Tamiya GAZ was the 'palette' for a number of techniques. First, the windshield; I mixed Testors Dullcote with ModelMaster Dark Tan to create a "dirt" much like you find your windshield after a week of harsh weather. This was smeared over the window areas after I cut a 'swipe' pattern from scotch tape.
The counterweight on the M36 features weld seams made from .010 plastic rod by Plastruct. The rod was coated with liquid cement to soften it. It was then applied to the turret with a round file that textured the simulated "weld seams."